For example, Japanese Laid-Open Patent Publication No. 2006-150460 and Japanese Laid-Open Patent Publication No. 2001-138162 each disclose a tool holder having a single anti-vibration ring on the outer circumferential portion.
Also, Japanese Patent No. 3836606 of the applicant of the present invention discloses a tool holder in which an anti-vibration ring is held by a rubber O-ring.